But there are too many variables. If your site is about coatamundis riffing on how to say "leaf blower" in Burushaski, that's one size of target audience. If it's about cats, that's a different size. How many people could see the site, vs. how many people actually do see it.
USA customers are usually those employed AND have internet/phone AND disposable income AND a desire to part with any funds. That number is diminishing daily. There might come a time when the site stats you're getting will be the envy of all.